11:30 〜 11:45
▲ [23a-B202-11] Discussion on 1D strain field induced flat bands in graphene and related pseudomagnetic fields
キーワード：graphene, pseudomagnetic field, strain
Modification of electronic structure of graphene by applying strain has been long researched topic in 2D material science. It was shown that strain field with triangular symmetry results in electron movement in graphene like those in magnetic field resulting in Landau quantization of electron energy levels. Such pseudomagnetic field (PMF) may be much stronger than true field achievable externally, and the direction of PMF depends on electron valley, opening a really exciting prospects in term of possible valleytronics application, and creation of highly correlated electronic systems. While creating truly triangular strain fields for uniform PMF may be difficult to achieve experimentally, there are attempts to create 1D ripple structures to induce 1D periodic PMF in graphene. Interestingly, applying simple PMF formulation as discussed in original work for 1D strain along zigzag edge direction in graphene results in zero PMF, the flat band quasi-Landau levels are still formed in full tight-binding calculations although in a very different manner compared in classical Dirac fermion system in magnetic field. In the present work we perform tight-binding calculations with band unfolding for various 1D periodic strain fields in graphene and discuss the results in the paradigm of possible pseudomagnetic and pseudoelectric fields and their applicability for description of resulting band structure modifications.